Shell mold casting machine



March 6, 1956 w, GRUENEBERG -r AL 2,736,936

SHELL MOLD CASTING MACHINE 2 Sheets-Sheet 1 Filed July 7, 1952 INVENTORS.

l L: W/[ZARD G. GRUENEBERG .1 E1 24 WILLIAM C. GRUENEBERG v BY BERNARD C. 5TOCKMANN March 5, 1956 w. G. GRUENEBERG ET AL 2,736,936

SHELL MOLD CASTING MACHINE Filed July 7, 1952 2 Sheets-Sheet 2 I L INVENTORS.

- WILLARD 6. GRUE/VEBERG BY WILL/AM C. GRUENEBERG BERNARD C. STOCK/MANN United States Patent SHELL MOLD CASTING MACHINE Willard G. Grueneberg, William C. Grueneberg, and Bernard C. Stockmann, Green Township, Hamilton County, Ohio Application July 7, 1952, Serial No. 297,524

6 Claims. (Cl. 2290) This invention relates to a shell mold casting machine, and more particularly relates to a machine for holding shell mold halves together and supporting the mold halves during pouring of molten metal into the mold to form a casting. More particularly, this invention relates to a machine for use in backing up and supporting molds of the type formed in the machine described and claimed in the application of Willard G. Grueneberg, William C. Grueneberg and Bernard C. Stockmann, filed July 3, 1952, Serial No. 297,052, for Method and Apparatus for Forming Shell Molds, during pouring of castings therein.

An object of the invention is to provide a machine for resiliently, and yieldingly urging two shell mold halves into face to face engagement.

A further object of this invention is to provide a shell mold casting machine having a plurality of resiliently urged pins which engage the shell mold halves to hold the halves together, and provide support for the mold halves during pouring of a casting.

A further object of this invention is to provide a machine of this type having pins which can be adjusted to allow for the external shape of shell molds.

A further object of this invention is to provide a shell mold casting machine having a plurality of yieldably urged groups of pins for engaging the opposite sides of shell mold halves and means for separating the groups of pins when a casting has been formed.

The above and other objects and featuresof the invention will in part be apparent and will in part be obvious from the following detailed description and the drawings, in which:

Figure 1 is a plan view of a shell mold casting machine constructed in accordance with an embodiment of this invention;

Figure 2 is a view in side elevation of the machine;

Fig. 3 is an enlarged view partly in side elevation and partly in section showing details of one of the mold holding pins of the machine;

Fig. 4 is a view in lengthwise section of another form of pin; and

Fig. 5 is a plan View of a shell mold casting machine constructed in accordance with another embodiment of this invention.

In the following detailed description, and the drawings, like reference characters indicate like parts.

As shown in Figs. 1 and 2, a shell mold casting machine includes a table supported by appropriate legs 12. A mold holder 13 is mounted on top of table 10. Themold holder is U-shaped, and includes a horizontal base number 14 and upwardly projecting side arms 15 and 16. Arms 15 and 16 are of channel shape with the flanges thereof directed inwardly. The mold holder 13 is adapted to support a pair of shell mold halves 17 and 18 with. the flanges of side arms 15 and 16 holding the mold halves in upright position. The mold halves may be held together by clips 19 and the mold halves are relatively loosely supported in mold holder 13. The mold holder serves to keep the mold halves substantially upright until mold back-up units, to be described hereinafter, are brought into position to support the mold halves during pouring of a casting, and, during the pouring of the casting, the mold holder catches any metal which may escape at the sides of the mold halves during pouring.

The mold halves are supported during pouring by means of a plurality of spring pressed pins 22. The pins 22 are arranged in banks on opposite sides of the mold holder. The bank of pins on the right hand side of mold holder 13, as shown in the drawings, is supported by an upright stationary back-up plate 23, while the bank of pins on the left hand side of mold holder 13 is supported by an upright movable back-up plate 24. Stationary back-up plate 23 is attached to table 10 and is held firmly in position thereon by struts 25. Movable back-up plate 24 is mounted in a rack bar 26 and can be advanced toward and away from mold holder 13. The rack bar meshes with a pinion 27. Pinion 27 may be turned by means of a crank 28 to advance the movable back-up plate.

All of the pins 22 are of similar construction, and details of construction of only one pin and the support therefor will be described in detail. In Fig. 3, pin 22 and the structure supporting pin 22 are shown. Pin 22 is mounted inside an elongated thimble 31 and can slide back and forth therein. The pin is provided with a collar 32 inside the thimble. Collar 32 forms a stop limiting advance of the pin to the right as shown in Fig. 3, and also forms a spring abutment which engages one end of a spring 33. Spring 33 is a compression coil spring and is mounted inside thimble 31 surrounding pin 32. The ends of thimble 31 are closed by caps 34 and 36. Cap 34 forms a back-up for the other end of spring 33, and serves as a guide for one end of pin 22 while cap 36 is adapted to be engaged by stop collar 32 to limit advance of the pin and also guides the other end of pin 22.

Thimble 31 is mounted in an opening 37 in a back-up plate 24. The thimble is externally threaded, as shown, and may be advanced to the right or to the left through opening 37 to adjust the normal position of pin 22. When thimble 31 is in proper or predetermined position, nuts 38 and 39, which are threaded to the outer surface thereof, are turned into engagement with plate 24 to lock the thimble in position in plate 24.

The pin shown in Fig. 3 is spring-pressed, so that, when plate 24 is advanced toward mold holder 19, pin 22 is brought into engagement with one of the shell mold halves, pin 22 resiliently holds and supports the shell mold half during pouring of a casting. When the machine shown in Figs. l-3 inclusive is in use, moveable plate 24 is first withdrawn to the left to the position shown in Fig. 2. The shell mold halves are then placed in mold holder 13, and crank 28 is turned to bring plate 24 and rack bar 26 to the position shown in Fig. 1 in which all the pins engage and resiliently hold the shell mold halves. The rack bar may be locked in this position by a lock screw 40 while metal is poured into the shell mold halves. When the metal has set sufiiciently, lock screw 40 is released and crank 28 is turned to withdraw rack bar 26 and moveable plate 24 to release the pins from the mold halves whereupon the casting and mold halves can be removed from mold holder 13. The shell mold halves are very thin, as shown, and are porous so that gases formed during pouring as the binder thereof burns out are quickly dissipated.

In Fig. 4 is shown an alternate form of pin 41. Pin 41 is mounted in a thimble 42. Thimble 42 is received in an opening 43 in a back-up plate 44. Nuts 46 and 48 hold the thimble 42 in place in opening 43. Pin 41 is attached v to a diaphragm 49. Diaphragm 49 is held between a diaphragm housing 51 and diaphragm cap 52 which form a hollow chamber divided by the diaphragm into two portions. The diaphragmhousing is threadedto one end of thimble 42. Compressed airor other fluid .can be introducedtintodiaphragmcapfl through a line .53, and when fluid .pressure is introduced into cap 52, pin 41 ,is driven to the right as shown in Fig. 4. When .the ,pressure is released, the pin 41 and diaphragm 49are returned to the position shown in Fig. 4- by a spring 54. Spring 54- is mounted inside diaphragm housing 51 surrounding pin 41 vandurges the pin to the left as shown in Fig. 4. A collar 56 on pin 41 limits advance thereof to .the left, while a washer 57 mounted on pin 41 limits advance thereofto the right, as shown inFig. 4-.

In Fig. 5 is illustrated schematically another machine for shell mold casting. The machine shown in Fig. 5 includes a table 61 which is rotatably mounted upon appropriate bearings, not shown. Table 61 carriesa plurality of mold holding plates 62. Each mold holding plate supports a mold holder 63 and also a mold back-up plate 64, attached thereto. Each mold back-up plate carries a plurality of pin holding thimbles 65and pins .66 held thereby, each of which may be similar in construction to the corresponding part of the machine described above and shown in Figs. 1 to 3 inclusive. As the table 61 is turned each mold holding plate 62 may be advanced in turn to a loading position A at which a pair of shell molds is inserted in the mold holder thereof. Then, the plate 62 may be advanced to a position B where a casting is poured and finally, to positions C, D, E, and F, at one of which the pair of molds may be removed from the mold holder together with the casting therein.

At casting position B, a movable back-up plate 67 is provided. Movable back-up plate 67 is mounted on a reciprocating rod 68. The rod 53 carries a piston 69 disposed in an appropriate cylinder 71. As will be understood, fluid under pressure may be introduced into the cylinder through a line 72 to drive the piston and backup plate toward the mold holder at station B. Plate 67 carries a plurality of pin holding thimbles 73 and pins 74. When plate 67 is advanced toward the mold holder 63 at station B, the pins supported by plate 67 come into engagement with one of the shell mold halves while the other shell mold half is engaged by the pins supported by the stationary plate 64 at station B. When acasting has been poured at station E, iiuid pressure is introduced into cylinder 71 through a line 75, to cause the piston 69 to draw back-up plate 67 away from the mold holder, releasing the mold halves, so that the table can be advanced to bring the next mold holder into position at station E.

The shell mold casting machines illustrated in the drawings and described above, firmly support both halves of apair of shell molds during the pouring of a casting and give sufiicient support to the shell mold halves so that they can withstand the static pressures involved in pourmg.

The machines illustrated in the drawings and described above are subject to structural modification without departing from the spirit and scope of the appended claims.

Having described our invention, what we claim as new and desire to secure by Letters Patent is:

l. A shell mold casting machine which comprises a base, means mounted on said base for supporting a pair ofshell mold halves in closed position, said mold supporting means comprising spaced upright members, each of said members having spaced inwardly extending flanges for receiving opposite ends of the mold halves to retain the mold halves in upright position, the spacing between the flanges of each upright member being greater than the thickness of the ends'of said mold halves, an upright stationarymold back-up plate mounted onsaid'baseon one side .of ,said mold supporting means, a pluralityof substantially horizontal rreciprocably mounted pins carried by said stationary plate and engageable with one of the shell mold halves, an upright movable mold back-up plate mounted on said base'on the other side of said mold supporting means, a plurality of reciprocably mounted pins carried by said movable plate and engageable with the other mold half, means for resiliently urging each of said pins toward the mold halves, each of said pins being independently reciprocable, and means for advancing the movable plate towards the stationary plate, whereby the pins are adapted to engage opposite sides of the pair of shell mold halves and hold the shell mold halves together with the mold halves disposed between and free'of the flanges of the upright members.

2. A casting machine in accordance with claim 1 characterized by the fact that each of said pins projects through an opening in the plate associated therewith, that the pin is supported in a thimble projecting through said opening with the mold engaging-end of the pinlprojecting from the thimble, that each thimble carries the means for resiliently urging the pin carried thereby,.and that the thimble is adjustably .advancable through the opening, whereby the normal position of each pin is adjustable.

3. A shell mold casting machine which comprises a rotatable table, a plurality of shell mold holders mounted on said table, each holder being adapted to support a pair of mold halves with the mold halves substantially perpendicular to the table and extending tangentially thereof, each mold holder comprising spaced upright members, each of said members having spaced inwardly extending flanges for receiving oppositeends of the mold halves supported thereby to retain the mold halves in upright position, the spacing between theflanges of each upright member being greater than the thickness of the ends of said mold halves, an upright mold back-up plate movable radially of the table, a plurality of substantially horizontal reciprocably mounted pinscarried'by said movable plate and engageable with one of .a pair of shell mold halves supported by the one of the mold holders when the table is stationary with said one of the mold holders on the radius of the movable plate, another mold back-up plate attached to the table on the side of each mold support opposite the movable plate, a plurality of substantially horizontalreciprocably mounted pins mounted on each of such other'plates, means for resiliently urging each of said pins in mold-engaging direction,.and each of said pins being independently reciprocable, means for advancing the movable plate radially of the table to bring the pins thereof into'engagernent with one of the pair of mold halves in said one of the mold holders when the mold holder is on the radius of the movable plate, the pins of the plate attached-to the table 'and associated with said one of the mold holders engaging the other of the mold halves in said one of the mold holders to hold the mold halves together with the mold halves disposed between and free of the flanges of the upright members, the table being turnable to bring each mold holder opposite the movable plate in turn.

4. A casting machine in accordance with claim 3, characterized by the fact that the movable plate is disposed on the inside of the mold holders and that the'stationary plates are disposed outside the mold holders.

5. A mold holder for backing up .a shell mold half which comprises an upright plate having a plurality of openings therethrough, a thimble projecting through each of said openings, a pin slidable lengthwise inside each of said thimbles, a spring in each thimble urging the pin mounted in the thimble toward the shell mold half, whereby each pin reciprocates independently, all pins being resiliently urged in the same direction,'a stop limiting advance of each pin to a normal position, and means for locking each thimble in predetermined positions in the opening associated therewith,'whereby the normal positions ofthe pinsare-adjustable.

6.,A mold i holder. forfhacking up a shell mold half which comprises an upright plate having a plurality of openings therethrough, an externally threaded thimble projecting through each of said openings, a pair of nuts mounting on each of said thinibles, each of said nuts being engageable with one face of the plate, whereby the nuts hold the thimble in predetermined positions of adjustment, a pin slidable lengthwise of and inside said thimble, a compression coil spring inside said thimble surrounding the pin, the pin having a collar inside the thimble spaced between the ends thereof and engaging one end of said spring, the spring urging the pin toward the shell mold half, whereby each pin is resiliently urged and reciprocates independently, and a pair of caps closing the ends of said thimble, each of said caps having an opening coaxial with the thimble in which one end of the pin is received for guiding the pin, said collar engaging one of said caps when the pin is released to hold the pin in a normal position, the other end of the spring engaging the other cap.

References Cited in the file of this patent UNITED STATES PATENTS 800,753 Mistelski Oct. 3, 1905 1,453,176 Perrine Apr. 24, 1923 1,499,989 Lehmann July 1, 1924 1,696,670 Byerlein Dec. 25, 1928 1,765,653 Carlson June 24, 1930 2,028,790 Lund Jan. 28, 1936 2,088,123 Toman July 27, 1937 2,399,824 Pressman May 7, 1946 2,651,822 Davis Sept. 15, 1953 2,660,770 Davis Dec. 1, 1953 

